Nio, known as the Tesla of China, is soaring, up more than 35%, during its second day of trading as a public company on US markets despite receiving an "underperform" rating.

On Thursday, Bloomberg reported Bernstein analyst Robin Zhu slapped an "underperform" rating on shares with a price target of $4.20 — some 36% below where shares settled on their first day of trading. Zhu sees a capital raise coming in the next 12 to 18 months.

The Chinese electric-car maker that's backed by Tencent had a disappointing debut on US public markets Wednesday as shares opened at $6 apiece, shy of the $6.26 initial-public-offering price. Nio raised $1 billion through the IPO, missing the $1.8 billion that it had targeted.

And while Nio's IPO was a big one, it's not the largest by a Chinese firm on US markets this year. iQiyi, known as the Netflix of China, raised $2.42 billion from a Nasdaq IPO in March. Pinduoduo, an online group discounter, is the second largest at $1.63 billion.